<template>
    <div class="tags" v-if="showTags">
        <scroll-pane class="tags-view-wrapper" ref="scrollPane">
            <ul>
                <li :class="{'active': isActive(item.path)}" :key="index" class="tags-li"
                    v-for="(item,index) in tagsList">
                    <router-link :to="item.path" class="tags-li-title" ref="tag" tag="span">
                        <span v-if="item.show === 'icon'">
                            <i :class="item.icon"></i>
                        </span>
                        <span v-else>{{item.title}}</span>
                    </router-link>
                    <span @click="closeTags(index)" class="tags-li-icon" v-if="item.closable"><i
                        class="el-icon-close"></i></span>
                </li>
            </ul>
        </scroll-pane>
        <div class="tags-close-box">
            <el-dropdown @command="handleTags">
                <el-button size="mini" type="primary">
                    标签选项<i class="el-icon-arrow-down el-icon--right"></i>
                </el-button>
                <el-dropdown-menu  slot="dropdown">
                    <el-dropdown-item command="other">关闭其他</el-dropdown-item>
                    <el-dropdown-item command="all">关闭所有</el-dropdown-item>
                </el-dropdown-menu>
            </el-dropdown>
        </div>
    </div>
</template>

<script>
    import bus from './bus';
    import ScrollPane from './ScrollPane';
    import router from '@/router';

    export default {
        components: {ScrollPane},
        data () {
            return {
                tagsList: [],
                refreshTab: '',
            }
        },
        computed: {
            showTags () {
                return this.tagsList.length > 0;
            }
        },
        watch: {
            $route (newValue, oldValue) {
                this.setTags(newValue);
                this.moveToCurrentTag();
            }
        },
        created () {
            this.setUnCloseTags();
            this.setTags(this.$route);
            // 监听关闭当前页面的标签页
            bus.$on('close_current_tags', () => {
                for (let i = 0, len = this.tagsList.length; i < len; i ++) {
                    const item = this.tagsList[i];
                    if (!item.closable) {
                        break;
                    }
                    if (item.path === this.$route.fullPath) {
                        if (i < len - 1) {
                            this.$router.push(this.tagsList[i + 1].path);
                        } else if (i > 0) {
                            this.$router.push(this.tagsList[i - 1].path);
                        } else {
                            this.$router.push('/');
                        }
                        this.tagsList.splice(i, 1);
                        break;
                    }
                }
            });
            // 监听关闭当前页面的标签页
            bus.$on('close_tags', (path) => {
                let tagIndex = -1;
                this.tagsList.forEach((item, index) => {
                    if (item.path === path) {
                        tagIndex = index;
                    }
                });
                if (tagIndex !== -1) {
                    this.tagsList.splice(tagIndex, 1);
                }
            });
        },
        methods: {
            moveToCurrentTag () {
                const tags = this.$refs.tag;
                this.$nextTick(() => {
                    if (tags) {
                        for (const tag of tags) {
                            if (tag.to === this.$route.path) {
                                this.$refs.scrollPane.moveToTarget(tag);
                                break
                            }
                        }
                    }
                })
            },
            setUnCloseTags (list) {
                let _this = this;
                if (!list) {
                    list = router.options.routes;
                }
                list.forEach(item => {
                    if (item.meta && item.meta.closable !== undefined && !item.meta.closable) {
                        this.tagsList.push({
                            title: item.meta.title,
                            closable: item.meta.closable,
                            show: item.meta.show,
                            icon: item.meta.icon,
                            path: item.path,
                            name: item.meta.title,
                        })
                    }
                    if (item.children && item.children.length > 0) {
                        _this.setUnCloseTags(item.children);
                    }
                });
            },
            isActive (path) {
                return path === this.$route.fullPath;
            },
            // 关闭单个标签
            closeTags (index) {
                const delItem = this.tagsList.splice(index, 1)[0];
                const item = this.tagsList[index] ? this.tagsList[index] : this.tagsList[index - 1];
                if (item) {
                    delItem.path === this.$route.fullPath && this.$router.push(item.path);
                } else {
                    this.$router.push('/');
                }
            },
            // 关闭全部标签
            closeAll () {
                this.tagsList = this.tagsList.filter(item => {
                    return !item.closable;
                });
                this.$router.push(this.tagsList.length > 0 ? this.tagsList[0].path : '/');
            },
            // 关闭其他标签
            closeOther () {
                this.tagsList = this.tagsList.filter(item => {
                    return !item.closable || item.path === this.$route.fullPath;
                });
            },
            // 设置标签
            setTags (route) {
                let oldTab = this.refreshTab;
                this.refreshTab = route.meta.refreshTab;
                const isExist = this.tagsList.some(item => {
                    return item.path === route.fullPath;
                });
                if (!isExist) {
                    let title = this.$utils.replaceTag(route);
                    this.tagsList.push({
                        title: title,
                        closable: route.meta.closable === undefined ? true : route.meta.closable,
                        show: route.meta.show,
                        icon: route.meta.icon,
                        path: route.fullPath,
                        name: route.matched && route.matched[1].components.default.name
                    });
                }
                bus.$emit('tags', this.tagsList);
                if (this.$utils.isNotEmpty(oldTab) && oldTab === route.meta.refreshTab) {
                    bus.$emit('refreshTab');
                }
            },
            handleTags (command) {
                command === 'other' ? this.closeOther() : this.closeAll();
            }
        }
    }

</script>


<style>
    .tags {
        position: relative;
        height: 30px;
        overflow: hidden;
        background: #fff;
        padding-right: 120px;
        display: block;
        /*box-shadow: 0 5px 10px #ddd;*/
    }

    .tags ul {
        box-sizing: border-box;
        width: 100%;
        height: 100%;
    }

    .tags-li {
        margin: 3px 5px 2px 3px;
        border-radius: 3px;
        font-size: 12px;
        cursor: pointer;
        height: 23px;
        line-height: 23px;
        border: 1px solid #e9eaec;
        background: #fff;
        padding: 0 5px 0 12px;
        vertical-align: middle;
        color: #666;
        -webkit-transition: all .3s ease-in;
        -moz-transition: all .3s ease-in;
        transition: all .3s ease-in;
        display: inline-block;
        position: relative;
    }

    .tags-li:not(.active):hover {
        background: #f8f8f8;
    }

    .tags-li.active {
        color: #fff;
    }

    .tags-li-title {
        float: left;
        /*max-width: 80px;*/
        overflow: hidden;
        white-space: nowrap;
        text-overflow: ellipsis;
        margin-right: 5px;
        color: #666;
    }

    .tags-li.active .tags-li-title {
        color: #fff;
    }

    .tags-close-box {
        position: absolute;
        right: 0;
        top: 0;
        box-sizing: border-box;
        padding-top: 1px;
        text-align: center;
        width: 110px;
        height: 30px;
        background: #fff;
        box-shadow: -3px 0 15px 3px rgba(0, 0, 0, .1);
        z-index: 10;
    }

</style>
